Efforts have been made to improve fuel injectors, particularly the fuel nozzle heads, to achieve better atomization of fuel and durability, as conventional gas turbine fuel nozzle heads have shortcomings. For example, carbon build-up or coking on the nozzle body is a problem. One solution to overcome coking is to provide an extremely smooth surface adjacent the nozzle head tip in order to reduce surface friction. However, this is an expensive and often unpractical solution.
Therefore, there is a continuing need for improved gas turbine fuel nozzle heads which control both the fuel spray pattern in an effective and economical manner, facilitating carbon free nozzle tips and efficient cold start operability and low pollutant emissions.